LST-5 Series UHF Radios

© Brooke Clarke 2010 - 2023

Background
Auxiliary Equipment
    PTPC-100 Control & PTPE-100 Amp
    LSSC-100 Communications Terminal
Accessories
    PTKY-104 KY-57 Cable
    LSBC-102 Battery Charger
Antennas
Power Supplies
    PTL-200 Battery Pack
    WKW-5 DC Power Adapter
Versions
Modifications
Operation
Related
Links


Fig 0
LST-5B radio w/ D&M C152-1-1 SATCOM  Antenna & LS-454 (modified) Speaker in Field
LST-5B
                SATCOM radio w/ D&M C152-1-1 Antenna in Field

Fig 1 Front Panel
LST-5B
                Front Panel

















X-Mode Con:
MS3114E16-26S
Fig 2 Front, Left (Label) & Top
LST-5B Left
                Front

Fig 3 Rear, Left (MWO) and Top
LST-5B
                Right Rear


Background

The LST-5 series was developed by Motorola starting in 1984.  They operate in the military UHF band between 225 and 400 MHz.  This is the band used my military aircraft and satellites.  Motorola made the LST-5A, LST-5B, LST-5C, LST-5D and LST-5E (aka AN/PSC-10()) .  The first DAMA (Wiki)  contract was to Magnavox (later Hughes then Raytheon) in 1994 as the PSC-5.  In Nov 1995 Motorola started selling it's LST-5D units.  In year 2000 Motorola developed a Remote Control Unit (RCU) to allow the radio operator to be in a location where there is not satellite visibility.  ( A radio operator on a mountain top anywhere near an enemy is called a target).

The radio supports AM (2 or 5 W), FM (4 to 20 W), Voice and data (MIL-STD-188C) using 1200 bps BPSK and DBPSK modulation as well as 2400 bps shaped BPSK modulation.

The DAMA system is being phased out.  The problem is that someone with a higher priority (say a general ordering coffee) will bump communications with a lower priority (say a special ops team).  The replacement will be a system using MELP vocoding (Wiki) and digital data transmission.

This radio supports use for satellite communications or terrestrial Line Of Sight (LOS) communications.  A military UHF LOS only radio typically only has an output power of a few watts whereas this radio has up to 20 Watts of output power.  Note to achieve the high power either an AC supply or a rechargeable battery must be used.  The BA-5590/U primary battery is limited to 2.25 Amps by an internal fuse and trying to use it for high power operation will blow the fuse in the battery (or maybe the fuse that's inside the LST-5B?

Auxiliary Equipment

AN/CSZ-1 Sunburst Cryptographic Processor
ANDVT - KY-99 Advanced Narrow-band Digital Voice Terminal (ANDVT)
KY-57/KY-58 - KY-57 Transmission Security Device
AM-7175/URC - 200 Watt RF amp (PTPA-200A)

PTPC-100 Control & PTPE-100/PTPE-101

 225 - 270 MHz 13 dB gain low noise Preamplifier
PTPC-100
                Control & PTPE-100/PTPE-101 225 - 270 MHz 13 dB gain
                low noise Preamplifier
PTPE-101 Connectors:
J1 Control: Type-Nf
J2 Antenna: Type-Nf


















PTPC-100 Control Connectors:

J1 X-Mode: MS3114E14-19P
J2 KY-57/58: MS3114E14-19S
J3 XCVR/PA: Type-Nf
J4 Pre-Amp: Type-Nf

LST-5 X-Mode Con:
MS3114E16-26S

KY-57 Radio Cable Conn:
MS3126E14-19S


LST-5 to PTPC-100 cable connectors:
PTPC-100 end:
LST-5 end:

KY-57 to PTPC-100 cable connectors:
PTPC-100 end:
KY-57 end:








DMDG - Digital Message Device Group - Special Forces Burst Communications System
AN/PSC-3 man-pack satellite radio & AN/VSC-7 vehicle Radio
KG-34 Shipboard/Fixed Plant: Key Generator, Electronic Full-Duplex, Jun 1971 - voice system used with separate vocoder.
KG-84 NSA Digital Data Security device (Wiki)
UYA-7 Digital Data Group
UGC-129 Teletypewriter Set
PC computer using special X-mode cable.

LSSC-100 Communications Terminal

Part # 01-P32561A001 - holds the LST-5 and a KY-57 and has a small control panel.
LSSC-100 Communications Terminal
overall top view
LSSC-100 Communications Terminal
AN/CSZ or KY-57 on left
LST-5 on right
LSSC-100 Communications Terminal
Battery box or Power Supply behind control panel

Retransmission can by done by connecting two radios using a special AUDIO cable p/n 30-P27587D001,  It's a "Y" cable with provision for a handset.
For crypto retransmission a special cable with four X-mode connectors is required. (it will be expensive, bulky and heavy).

Accessories

LSAD-100 11-32 VDC or 120/240 VAC Power Supply
PTA-200 115/230 VAC Power Supply
HYP-5 15-30 VDC Power Adapter
PDFA-101 Mil Vehicle power adapter with VIC-1 type DC input and DC output 4 terminal connectors, like on MT-1029
Remote Control Unit (RCU)
Vehicle & Aircraft mount
Data & Control Cables

PTKY-104, 30-P27585D002, 94990 Cable

KY-57 or CSZ-1 to LST-5, LST-5A, LST-5B X-Mode

Fig 1.
PTKY-104,
                    30-P27585D002, 94990 Cable KY-57 or CSZ-1 to LST-5,
                    LST-5A, LST-5B X-Mode
Fig 2
PTKY-104,
                    30-P27585D002, 94990 Cable KY-57 or CSZ-1 to LST-5,
                    LST-5A, LST-5B X-Mode
KY-57
RADio
KY-57
Function
LST-5
X-mode
A
Rx CT in
B


C
PT in
D

P
E
Rx Data out nc
F

nc
G
Gnd A, shell
H
Gnd A, shell
J


K


L
PT or ? D
M
PT out C
N
Tx Data in R
P

nc
R
DCD A, shell?
S
PTT shell?
T
Tx Clk L
U
Tx CT out B
V

nc
Spare parts & Module kit
Training Programs & Equipment

LSBC-102 Battery Charger

LSBC-102 Battery Charger

LSBC-102 Battery Charger
The input can be either:
95 - 260 VAC @ 47 - 440 Hz
or
11 - 36 VDC
LSBC-102 Battery Charger
Toggle Switch:
BB-490
or
BB-390/BB590
or
BB-690

Red Push-button:
Push for Discharge Cycle

LED for the A and B sides
Green for charge
Yellow for discharge


KeCo Switch
allows easy switching between LOS and Satcom antennas.
6975178 Military communications antenna switching, Donald J. Kessler, David N. Coates, Dec 13, 2005, 333/105, 455/78, 343/906, 333/262, 455/90.1 -


Antennas

Line Of Sight (LOS)

These are the dildo type antennas like used on the RT-1319 (PRC-113).

Satellite

These are the circular polarization tripod mounted like the Dorne & Margolin.
Antenna
Gain
dB
D&M C125-1
5
D&M C120
6
D&M C121-1
10
D&M C122-2
12
D&M C152-1-1
?

Power Supplies

The radio has a DB-9m connector on the rear (bottom) face (Fig 2) that interfaces with the power supply.
Pin
Function
1 & 6
On/Off sw
3
+24 to radio
5
Ground
2, 4, 7, 8, 9
n.c.
Note: the Radio On/Off switch is brought out as two isolated contacts at pins 1 & 6 so that a relay can be used to turn the power supply on and off.  This is very handy when an AC power supply is being used.

PTL-200 Battery Pack

The battery pack holds any of the BA-5590 family of batteries (or my 5590BA battery adapter) although the LST-5A and LST-5B only had the BB-590 or BA-5590 available at that time. 
Note:  Exceeding 10 Watts output power may blow the fuse in a BA-5590/U battery.  Use a rechargeable battery (BB-590, BB-390, BB-2590, etc.) for power levels above 10 Watts.

WKW-5

This is a battery eliminator with the DB-9 connector on the radio side and a MS3470W14-5P for the DC input. 
The input is 28 VDC and Vout to be 24 VDC, not sure why the difference.

The input goes through a full wave bridge, so the input polarity does not matter.
Then a EMP filter.
Then a relay that is controlled by the radio in typical fashion for the LST-5 type radios.

Input connector Panel:MS3470W14-5P, Cable: ___TBD___

MS3470W14-5P
Pin
Function

DB-9
wire
Function
Relay
A
DC
1
Red
+28
A2 & B2
B
DC
5 & 6
Blk
-28 Gnd
Coil
C
nc
9
Wht

Coil
D
nc
3
Wht

A1 & B1
E
nc
7
Wht

A1 & B1

MS3470W14-5P

LST-5 WKW-5
                      Power Adapter


DB-9f pin1 lower right, pin5 top right
pin 6 upper left, pin 9 lower left

LST-5 WKW-5
                      Power Adapter


Inside

LST-5 WKW-5
                      Power Adapter


Memory Battery

There is an LTC-7PN 3.5 V battery soldered on the CPU board that maintains the preset data.  It's supposed to be replaced once every 2 years.
This radio has a paper sticker with a date of 01FEB01 and today is 04JUN2010 so the battery is over 9 years old and still working.

Versions

LST-5A

For s/n in the range below F178 there is a 7th mode for real time clock & Calander.
No modem.  Maybe OD in color.

LST-5B

Adds an internal modem.

LST-5C

When the BA-5590 Lithium battery is used the "C" radio will develop full output power.  This means that the radio draws less than 2.25 Amps at 20 volts.  This requires a more efficient RF power amplifier than the one used in the "A" and "B" versions.
Front panel fuse above and to the right of the handset connector, instead of an internal fuse.

LST-5D

Adds Demand Assign Multiple Access (DAMA) which reassignes the satellites bandwidth based on the priority of the calls that are active.  This is similar to the system used on the autovon telephone network.  For example see the TA-1042 info on Flash Override, etc.

LST-5E

Adds embedded encryption (CSZ-1A Sunburst II).  The "B" or "C" models can be upgraded to "E".

Modifications

The MWO sticker has had 1, 2, 3, 4 & 5 Blacked out leaving 6 to 18 showing.
If you know what these mods were please let me know.

Operation

See the Front Panel photo (Fig 1).
When the MODE button is pressed the display cycles through the six main menu pages.  A mode chart is printed on the top (Fig 3) of the radio.
The CUR button moves the cursor horizontally to each of the fields that can be changed.
The SET button increments the field.
The STO button saves the change to memory.
LST-5B display 1. Frequency
1. Frequency

The 4 - <blank>
should be
4 - 1 (spluit freq chan)
the cursor was on the 1
and the camera shutter
opened with the blink was
blank.
When both the 4 and the 1
are blinking, pressing SET
causes the display to show
CH1.  When SET is now
pressed you can see the channels.
CH1: 265550
CH4: 297850
delta: 2.3 MHz
LST-5B display 2. Configuration
2. Configuration
These are like toggle switches, shown:
FM (or AM)
 XHI (or Tx pwr low)
CT (or plain text)
SCN:OFF (or scan on)
BCN:OFF (or beacon on)
LST-5B display 3. SELCAL
3. SELCAL
the Tx code (center of display) is 00
the Rx code (at the right) is also 00
LST-5B display 4. Meter
4. Meter
showing SI 6 (Rx Sig str) & no bars
when transmitting it will show:
PO  and bars (2 Watts per bar)

LST-5B display 5. Modem Control
5. Modem Control
showing 24 (or 12)
showing OFF (or on)
LST-5B display 6. Power Out
6. Power Out

Related

RT-1319 VHF-Hi & UHF Aircraft tranceiver
VRC-83 part of the GRC-206 FAC system

PSC-5 Portable SATCOM terminal
RT-1672 Multi-band Multi-mission communication terminal - supports voice and data modes both PT & CT
RT-1672 SATCOM
        radio (PSC-5)
RT-1672 SATCOM
        radio (PSC-5)

Wanted male & female versions of this connector to make extender card or extender cable.  Contact Brooke
80 terminal connector 0.075" pitch
RT-1672 80 terminal
        connector 0.075" pitch
RT-1672 Motherboard top
RT-1672
                Motherboard top
RT-1672 Power Supply PCB top
RT-1672
                Power Supply PCB top
RT-1672 Motherboard bottom
RT-1672
                Motherboard bottom
RT-1672 Power Supply PCB bottom
RT-1672
                Power Supply PCB bottom
TM 11-5820-1130-12&P

RADIO SET AN/PSC-5 (NSN 5820-01-366-412 (EIC: N/A) {TO 31R2-2PSC5-1; NAVELEX EE125-WU-OMI-010/PSC-5; TM 10191A-12&P/1}
TM 11-5820-1130-30&P1
RADIO SET AN/PSC-5 (NSN 5820-01-366-412 (EIC: N/A) {TO 31R2-2PSC5-2; NAVELEX EE125-WU-MMO-010/PSC-5; TM 10191A-30&P/2} (THIS ITEM IS INCLUDED ON EM 0169)
TM 11-5820-1131-12

 Links

Mike Murphy 
UHF-Satcom - a lot of info about UHF SATCOM
FM 6.02.90 Aug 2004 UHF TACSAT/DAMA - App E operating procedures for the LST-5D
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page created 2 Jun 2009.